This invention relates to an improved metal-hydrogen cell and, more particularly, the invention is concerned with providing a central heat pipe which serves as the positive plate conductor and terminal and the mechanical support for the stack as well as the thermal path for controlling the heat generated by the cell.
Heretofore, it has been common practice to provide a structural arrangement where the primary heat flow in the metal-hydrogen cell is from the outside edge of the cell stacks to the pressure vessel. In order to provide a thermal path, a minimum gap would be required placing the cell wall very close to the plate edges. Because of the close proximity of the cell wall and the plate edges, such occurrences as vibration and temperature or pressure variations within the cell can cause the outer edge of the cell stack to make contact with the cell wall. This can cause shorts in the cell stack. Also, damage in the form of bending of the substrate wires, chipping of active material and local destruction of the separator can occur when the battery is subjected to impact with the pressure vessel during launch when the cell is installed in a space vehicle or the like.
Thus, it would be desirable to provide a cell which would incorporate all of the advantages of the cylindrical cell without the obvious drawbacks noted above. The hereinafter described spherical heat pipe cell does overcome all of the disadvantages of the cylindrical cell and still allows substantial weight reduction with no loss of strength and reliability.